Fatty acids are molecules of wide application, both in foodstuffs and in industry. 2-Hydroxyoleic acid, the synthesis of which has been described previously (Adam et al., 1998, Eur. J. Org. Chem. 9, 2013-2018), has been used industrially as an emulsifier for preparations of cosmetics.
For example, on the one hand, patent JP 10182338 relates to an oil-in-water emulsifying composition that exhibits low irritability and high compatibility with salts, which contains: [A] nonionic surfactants such as polyoxyethylene sorbitol monolaurate, polyoxyethylene sorbitol monooleate and polyoxyethylene sorbitol monostearate, [B] 2-hydroxy C10-C22 fatty acids such as 2-hydroxystearic acid, [C] oils and [D] water, in which the A/B ratio is between 1:0.01 and 1:2.
Patent JP 09110635 also relates to compositions that can be used as pharmaceutical products, cosmetics and foodstuffs and contain: [A] esters of polyglyceryl fatty acid, [B] 2-hydroxy C10-C22 fatty acids, [C] oils and [D] water, where the weight ratio of A/C and B/C is 2.0 and 0.5 respectively, and have average particle sizes between 10 and 300 nm. These compositions show good stability even in acid conditions or at low viscosity or in the presence of elevated quantities of salts, and therefore are compatible with the skin.
On the other hand, this fatty acid has also been employed as an inhibitor of oleamide hydrolase, an action that is associated with the sleep inducing effect of this substance (U.S. Pat. No. 6,096,784 and WO 9749667).
For example, U.S. Pat. No. 6,096,784 relates to the design and synthesis of oleamide hydrolase inhibitors, responsible for the hydrolysis of a sleep-inducing lipid (cis-9-octadecenamide). The most potent inhibitors possess an electrophilic carbonyl group capable of forming, reversibly, a (thio)hemiacetal or a (thio)hemiacetal for imitating the transition state of a reaction catalyzed by a protease of the cisteine or serine type. In addition to the inhibitory activity, some of the inhibitors displayed agonistic activity that induces sleep in laboratory animals.
The Hexagonal Membrane Structures.
The membrane lipids are able to arrange themselves in a greater number of secondary structures than the proteins and nucleic acids. The typical lipid bilayer of biological membranes is just one of these secondary configurations. Little is known about the abundance and roles of other secondary structures in living cells. One function of these structures was described in a previous work of the inventors: to increase the binding affinity of G-proteins to membranes (Escribá P V, Ozaita A, Ribas C, Miralles A, Fodor E, Farkas and García-Sevilla J A; 1997 Proceedings of the National Academy of Sciences of the USA 94, 11375-11380).
The concept of membrane structure goes far beyond that described in some of the patents of the state of the art (WO 87/04926 and WO 80/11286), in which only membrane fluidity is mentioned, and the concept is extended to a much wider field: the membrane structure. The molecules covered by our patent act on the transition or passage from lamellar to hexagonal structure (FIG. 1).
Examining the prior art cited, in the state of the art there are no other applications connected with 2-hydroxyoleic acid or similar compounds that would be of particular interest in the area of cancer treatment, cardiovascular diseases and/or control of body weight.
There are only descriptions of dietary products (GB 2140668, EP 0611568 and WO 02/0042) or extracts from cultures of M. cryophilus (WO 89/11286), which consist of complex mixtures of various compounds that include some of those described in the invention, such as fatty acids, in particular oleic and palmioleic acids, for example, and the use of these mixtures in the treatment of arterial hypertension, for the control of obesity or as antitumor agents, but without ascribing to any of the components of the mixture considered in the present invention, a specific role in the said therapeutic effect. Only WO 02/051406 and WO 94/01100 describe the use of certain fatty acids (C14-C20) in the treatment of prostate cancer, which is not an object of the present invention, exclusively when using the said fatty acids described in the state of the art.